The Late Show host went on to say that Trump’s behaviour “unnerved a lot of people,” and he showed a tweet from former CIA director John Brennan, who criticized Trump for being “wholly in the pocket of Putin.”

Brennan also asked, “Republican Patriots: Where are you?”

Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of “high crimes & misdemeanors.” It was nothing short of treasonous. Not only were Trump’s comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???

Colbert showed a clip of the Trump-Putin press conference in which the Russian president asked if reporters believe the Russian government would try to obtain compromising information on 500 American businessmen attending a meeting in St. Petersburg, including Trump.

“Do you think we tried to collect compromising information on each and every single one of them?” Putin asked the press.

Colbert responded to Putin’s question saying, “Yeah. Yeah, I do. When I was in Russia – and this is true – I was followed everywhere I went and I’m a comedian. All right? I was informed by our security people in no uncertain terms that my phone was bugged and my room had cameras in it. So I showered in a blue blazer. When I finally, when finally I had to get naked eventually – and this is true – I turned to every mirror and said, ‘You like, Ivan? You like?’”

Watch part of Colbert’s monologue from Monday night in the video above.